The invention relates in general to polynucleotides and polypeptides encoded thereby. The invention relates more particularly to nucleotides encoding polypeptides related to human aortic carboxypeptidase.
The carboxypeptidases are a family of hydrolase enzymes that remove the amino acid at the free carboxyl (C) end of a polypeptide chain. Members of the carboxypeptidase family have been implicated in multiple biological activities.
Carboxypeptidases can be divided into at least two subfamilies of metallocarboxypeptidases. One subfamily includes the pancreatic carboxypeptidase-like subfamily. Its members include, e.g., carboxypeptidase A, carboxypetpidase A2, carboxypeptidase B, and carboxypeptidase B2.
A second subfamily includes regulatory B-type carboxypeptidases. Its members include, e.g., carboxypeptidase H, carboxypeptidease M , carboxypeptidase N, carboxypeptidase Z, AEBP1, ACPLX, Ms CPX1, and MsCPX2. Members of this subfamily have been implicated in activities that include regulation of polypeptide hormone processing activity and processing of extracellular peptides with carboxyterminal arginine residues. In addition, carboxypeptidases present at the surface of vascular smooth muscle cells, such as aortic smooth muscle cells, have been reported to exert a complex influence on the level of biologically active vasoactive peptides, e.g. bradykinin, angiotensin II, which influence the tone and caliber of blood vessels. Carboxypeptidases have also been reported to be are responsible for a catabolic inactivation of vasoactive peptides.
The present invention is based upon the discovery of a novel human nucleic acid sequence encoding a polypeptide having sequence similarity to previously described members of the carboxypeptidase. The aortic carboxypeptidase-like nucleic acids, polynucleotides, proteins and polypeptides, or fragments thereof described herein are collectively referred to as ACPLX nucleic acids and polypeptides. ACPLX nucleic acids include those found in SEQ ID NO: 1, and the polypeptide encoded by SEQ ID NO:2.
Accordingly, one aspect of the present invention includes an isolated aortic carboxypeptidase-like nucleic acid molecule that includes a nucleotide sequence encoding a polypeptide that includes the amino acid sequence of SEQ ID NO:2. In various embodiments, the nucleic acid molecule can include a nucleotide sequence that includes SEQ ID NO:1. Alternatively, the encoded aortic carboxypeptidase-like protein (ACPLX) may possess a variant amino acid sequence, thereby having an identity or similarity less than 100% to the disclosed amino acid sequences.
The invention further includes an isolated polypeptide that includes the amino acid sequence of SEQ ID NO:2. Also included is a variant of a mature form of the amino acid sequence, or a variant of the amino acid, given by SEQ ID NO:2. In various embodiments, no more than 15%, 10%, 9%, 8%, 5%, 3%, 2%, or 1% of the amino acid residues in the sequence are changed to a different amino acid.
The invention yet further includes an antibody that immunospecifically binds to ACPLX. In the preferred embodiment, the antibody is monoclonal and of human origin. Such antibodies are most useful in treating a pathological condition in a subject wherein the treatment includes administering the antibody to the subject.
Also included in the invention is a method of producing an ACPLX by culturing a host cell expressing the aortic carboxypeptidase-like nucleic acids, described herein, under conditions in which the nucleic acid molecule is expressed.
The invention yet further includes a method of detecting the presence of an aortic carboxypeptidase-like polypeptide in a sample from a mammal, e.g., a human, by introducing a sample from the mammal with an antibody that immunospecifically binds to one of the polypeptides, and then detecting the formation of reaction complexes including the antibody and the polypeptide in the sample. Detecting the formation of complexes in the sample indicates the presence of the polypeptide in the sample.
Also included in the invention is a method of detecting the presence of an aortic carboxypeptidase-like nucleic acid molecule in a sample from a mammal, e.g. a human, by introducing the sample with a nucleic acid probe that selectively binds to the nucleic acid, and then determining whether the nucleic acid binds to a nucleic acid molecule in the sample. Binding of the nucleic acid probe indicates the nucleic acid molecule is present in the sample.
The invention yet still further includes a method of identifying a potential therapeutic agent for use in the treatment of a pathology associated with altered levels of an aortic carboxypeptidase-like nucleic acid sample from a mammal e.g., a human. The method includes introducing a cell expressing the polypeptide with a composition that is a candidate substance for a therapeutic agent. Where the property or function of the candidate substance is altered in the presence of the cell, the substance is identified as a potential therapeutic agent.
The invention also includes a method of treating or preventing a pathological condition in a mammal e.g., a human, associated with the polypeptide described herein, by administering to the subject an ACPLX in an amount sufficient to alleviate the pathological condition. Alternatively, the mammal may be treated by administering an antibody, as described herein, in an amount sufficient to alleviate the pathological condition.
Pathological states for which methods of treatment of the invention are envisioned include a cancer e.g., breast and ovarian, hypertensive disorder, vascular endothelial disorders e.g. atherosclerosis, processing and/or transport of the vasopressin-ncurophysin pre-hormone product.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the case of conflict, the present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.
Other features and advantages of the invention will be apparent from the following detailed description and claims.